1. Field of the Invention
The present invention relates to a multi-terminal type laminated capacitor and a manufacturing method thereof.
2. Description of the Related Art
In an electric supply source of a central processing unit (CPU) mounted in a digital electronic device, a reduction in voltage advances while a load current is increased. Therefore, suppressing a fluctuation in power supply voltage within an allowable value range with respect to a sudden change in load current becomes very difficult, and hence a laminated capacitor called a decoupling capacitor is connected with a power supply. Further, at the time of a transitional fluctuation in load current, a current is supplied from this laminated capacitor to a CPU, thereby suppressing a fluctuation in power supply voltage.
In recent years, with a further increase in an operating frequency of a CPU, a load current and its speed are increased. Therefore, in the laminated capacitor used as the decoupling capacitor, there is a demand for an increase in equivalent series resistance (ESR).
In a multi-terminal type laminated capacitor disclosed in Japanese Patent Application Laid-open No. 2000-208361, an extraction electrode for connection with a terminal electrode is provided to an internal electrode in each layer, and such an extraction electrode is led onto a side surface of a ceramic porcelain. The terminal electrode is formed on the side surface of the ceramic porcelain by plating or the like and joined to the extraction electrode. The terminal electrode is appressed against the ceramic porcelain through a joining structure with respect to the extraction electrode.
In order to obtain a high ESR in this type of laminated capacitor, there can be considered a technique which reduces a film thickness of the internal electrode provided in each layer.
However, in the technology described in Japanese Patent Application Laid-open No. 2000-208361, since the film thickness of the extraction electrode is the same as the film thickness of the internal electrode, reducing the film thickness of the internal electrode decreases the film thickness of the extraction electrode. When the film thickness of the extraction electrode is reduced, a sufficient joining structure cannot be provided to the terminal electrode, and hence it is difficult to assure the adhesion of the terminal electrode with respect to the ceramic porcelain.
As another means for increasing the ESR, a technique of reducing the number of layers can be considered. However, when the number of layers is reduced, the number of extraction electrodes is also decreased. In the technology described in Japanese Patent Application Laid-open No. 2000-208361, the film thickness of the extraction electrode is the same as the film thickness of the internal electrode. Therefore, when the number of the extraction electrodes is reduced, a sufficient joining structure cannot be provided to the terminal electrode, and hence it is difficult to assure the adhesion of the terminal electrode with respect to the ceramic porcelain.